The measurement of the use of specialized feeding techniques by the digestive system with the aim of developing the best way of feeding patients with digestive diseases such as acute pancreatitis. Intravenous feeding is one of the greatest advances in the management of surgical and critical-care patients in modern times. It especially helps in complicated abdominal procedures promoting faster recovery and preventing malnutrition, reduced host defense, and slower healing of wounds. However, it poses some problems by not utilizing the body's natural functions and disrupts metabolic control exerted by the liver and pancreas on the inflow of nutrients into the bloodstream. In the disease of acute pancreatitis, feeding through the intestines (enteral feeding), may worsen the symptoms. So, intravenous feeding has been favored. In this study, the proposal is to compare the physiological effects of feeding through the intestines and the effects of feeding intravenously on the synthesis and secretion of pancreatic enzymes, first in healthy volunteers, and then in patients with acute pancreatitis. This will enable the design of the safest and most cost effective method of nutritional support for patients with acute pancreatitis. The study will involve healthy volunteers who will be randomly divided into four groups, each group using a different diet. Subjects will be admitted to the General Clinical Research Center at MCV. A feeding tube (NGtube) will be passed through the nose into the stomach, the stomach will be emptied with the help of a drug, a light dinner will be provided, and fasting will occur until the next morning. In the morning, an intravenous (IV) catheter will be inserted into an arm. Two different amino acids will be administered, one through the IV and one through the NG tube. During the test, half-hourly samples of digestive juice will be suctioned from the feeding tube to measure the amount of amino acids in the digestive enzymes. Blood and breath samples will be taken. At the end of the test, a tube will be passed into the stomach and intestine and intestinal lining will be taken for analysis.